Mammalian diversity

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T.M.M MAMPANE
216039130
LIFE SCIENCES ASSINGMENT

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PLANING SCHEDULE
LESSON TOPIC DURATION TEACHING METHOD
LESSON 1 INTRODUCTION
TO 3 MAJOR
LINEAGE OF
MAMMALS,
DEFINITIONS,
EXAMPLES OF
ANIMALS.
45 MINUTES Class discussion
LESSON 2 PHYLOGENETIC
RELATIONSHIPS
OF MAMMALS
45 minutes Class discussion
LESSON 3 PRIMATES
(DERIVED
CHARECTERS
OF PRIMATE)
45 minutes Class discussion
LESSON 4 LIVING
PRIMATES 1 hour minutes practical
LESSON 5 UNIT TEST 1 HOUR AND 30
MINUTES Unit test

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Unit 1
EXPLORING MAMMALIAN DIVERSITY
INTRODUCTION
Phylogenetic Relations of Mammals.
Evidence from numerous fossils and molecular analyses indicates that monotremes
diverged from other mammals about 180 million years ago and that marsupials
diverged from eutherians (placenta) mammals about 140 million years ago. Molecular
systematics has helped to clarify the evolutionary relationships between the eutherian
orders, though there is still no broad consensus on a phylogenetic tree, (Campbell,
2014)
1. The three major lineages of mammals that had emerged: those leading to…
 Monotremes (egg-laying mammals),
 Marsupials (mammals with a pouch) and
 Eutherians (placenta mammals) (Waters, 2007)
Monotremes
 Monotremes are found only in Australia and New Guinea and are represented
by one species of platypus and four species of echidnas (spiny anteaters;
Figure 34.37).
 Monotremes lay eggs, a character that is ancestral for amniotes and retained
in most reptiles.
 Like all mammals, monotremes have hair and produce milk, but they lack
nipples.
 Milk is secreted by glands on the belly of the mother. After hatching the, baby
sucks the milk from the mother’s fur. (Mayle, 1994)

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Figure 34.37 Short-beaked echidna (Tachyglossus aculeatus), and Australian
monotremes. Monotremes have hair and reproduce milk.but they lack nipples.
Monotremes are the only mammals that lay eggs (inset).
Marsupials
 Opossum, kangaroos, and koalas are examples of the group called
marsupials.
 Both marsupials and eutherians share derived characters not found among
monotremes.
 They have higher metabolic rates and nipples that provide mil, and they give
birth to live young.
 The embryo develops inside the uterus of the female’s reproductive tract.
 The lining of the uterus and the extraembryonic membranes that arise from the
embryo form a placenta, a structure in which nutrients diffuse from the mother’s
blood.
 A marsupials is born very early in its development and completes its embryonic
development while nursing (Figure 34-33a).
 In most species, the nursing young are held within a maternal pouch called a
marsupium.

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 A red kangaroo, for instance, is about the size of a honeybee at its birth, just 33
days after fertilization. Its back legs merely buds,
 but its front legs are strong enough for it to crawl from the exit of its mother’s
reproductive tract to a pouch that opens to the front of her body, a journey that
lasts a few minutes.
 In other species, the marsupium opens to the rear of the mother’s body; in
greater bilbies, this protects the young as their mother burrows in the dirt
(Figure 34-33b).
(a) A youngbrushtail possum. The offspring of marsupials are born very early
in their development. They finish their growth while nursing from a nipple (in
their mother’s pouch in most species).
(b) A greater bilby. The greater is a digger and burrower that eats termites and
other insects, along with the seeds, roots, and bulbs of various plants. The
female’s rear-opening pouch helps protect the young from dirt as the mother
digs. Other marsupials, such as kangaroos, have a pouch that opens to the
front.
 Figure 34-33 Australia marsupials.

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 Marsupials existed worldwide during the Mesozoic era, but today they are found
only in the Australian region and in North and South America.
 The biogeography of marsupials illustrates the interplay between biological and
geologic evolution.
 After the breakup of the supercontinent Pangea, South America a d Australia
became island continents,
 and their marsupials diversified in isolation from the eutherians that began an
adaptive radiation on the northern continents.
 Australia has not been in contact with another since early in the Cenozoic era,
about 65 million years ago.
 In Australia, convergent evolution has resulted in a diversity of marsupials that
resemble eutherians in similar ecological roles in other parts of the world
(Figure 34.39).
 In contrast, although South America had a diverse marsupials fauna throughout
the Paleogene, it has experienced several immigrations of eutherians.
 One of the most important occurred about 3 million years ago, when North and
South America joined at the Panamanian isthmus and extensive two-way traffic
of animals took place over the land bridge.
 Today, only marsupials live outside the Australian region, and the only
marsupials also found in the wild in North America are a few species of
opossum.
Figure 34.39

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Eutherians (PlacentalMammals)
 Eutherians are commonly called placental mammals because their placentas
are more complex than those of marsupials.

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 Eutherians have a longer pregnancy than marsupials.
 Young eutherians complete their embryonic development within the uterus,
joined to their mother by the placenta.
 The eutherian placenta provides an intimate and long-lasting association
between the mother and her developing young.
 The major groups of living eutherians are thought to have diverged from one
another in a burst of evolutionary change.
 The timing of this burst is uncertain: Molecular data suggest it occurred about
100 million years.
 while morphological data suggest it was about 60 million years ago.
 Figure 34.40 explores several major eutherian orders and their phylogenetic
relationships with each other as well as with the monotremes and marsupials.
(Campbell, 2014)
2. One current hypothesis,represented bythe tree shown below, clusters
the eutherian orders into four main clades.

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3. Primates
 The mammalian order primates include the lemurs, tarsiers, monkeys and
apes.
 Humans are members of the of the ape group.
Derived Characters of primates
 Most primates have hands and stead of the narrow claws of other mammals.
 There are other characteristic features of the hands and feet, too, such as
skin ridges on the fingers (which account for human fingerprints).
 Relative to other mammals, primates have a large brain and short jaws,
giving them a flat face.
 Their forward-looking eyes are close together on the front of the face.
 Primates also exhibit relatively well-developed parental care and complex
social behavior.

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 The earliest known primates were tree-dwellers, and many of the
characteristics of primates are adaptations to the demands of living in the
trees.
 Grasping hands and feet allow primates to hang onto tree branches.
 All living primates except humans have a big toe that is widely separated
from the other toes, enabling them to grasp branches with their feet.
 All primates also have a thumb that is relatively movable and separates from
the fingers,
 but monkeys and apes have a fully opposable thumb; that is, they can
touch the ventral surface (fingerprint side) of the tip of all four fingers with
the ventral surface of the thumb of the same hand.
 In monkeys and apes other than humans, the opposable thumb allows it to
be used for more precise manipulation.
The unique dexterity of humans represents descent with modification from our tree-
dwelling ancestors, (Campbell, 2014).
 Arboreal maneuvering also requires excellent eye-hand coordination.
 The overlapping visual fields of the two forward-facing eyes enhance depth
perception, an obvious advantage when brachiating (traveling by swinging
from branch to branch in trees).
4. Living Primates
 There are three main groups of living primates:
(1) the lemurs of Madagascar (Figure 34.41) and the lorises and bush babies
of tropical Africa and Southern Asia;
(2) the tarsiers, which live in the southeastern Asia; and
(3) the anthropoids, which involves monkeys and apes and are are found
worldwide
 The first group—lemurs, lorises and bush babies—probably resemble early
arboreal primates.
 The oldest known tarsier fossils date to 55 million years ago, while the oldest
anthropoid fossils date to 45 million years ago; along with DNA evidence, these

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fossils indicates that tarsiers are more closely related to anthropoids than to the
lemur group (Figure 34.42).
 Figure 34.41 Verreaux’s sifakas (Propithecus verreauxi), a type of lemur.

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Figure 34.42 a phylogenetic tree of primates. The fossil record indicates that
anthropoids began diverging from other primates about 55 million years ago. New
World monkeys, Old World monkeys, and apes (the clade that includes gibbons,
orangutans, gorillas, chimpanzees, and humans) have been evolving as separate
lineages for more than 25 million years. The lineages leading to humans branched off
from other apes sometimes between 6 and million years ago, (Campbell, 2014).
❇️ is the phylogeny shown here consistent with the idea that humans evolved
from chimpanzees?
 You can see in Figure 32.42 that monkeys do not form a clade but rather
consist of two groups, the New and Old World monkeys.
 Both of these groups are thought to have originated in Africa or Asia.

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 The fossil record indicates that New World monkeys first colonized South
America roughly 25 million years ago.
 By the time, South America and Africa had drifted apart, and monkeys
may have reached South America from Africa by rafting on on logs or
other debris.
 What is certain is that New World monkeys and Old World monkeys
underwent separate adaptive radiations during their many millions of
years of separation (Figure 34.43).
 All species of New World monkeys are arboreal, whereas Old World
monkeys include ground-dwelling as well as arboreal species.
 Most monkeys in both groups are diurnal (active during the day) and
usually live in bands held together by social behavior.
 The other group of anthropoids consists of primates in formally called
apes (Figure 34.44).
 The ape group includes the genera Hylobates (gibbons), Pongo
(orangutans), Gorilla (gorillas), Pan (chimpanzees and bonobos), and
Homo (humans).
 The apes diverged from Old World monkeys about 25–30 million years
ago.
 Today, nonhuman apes are found exclusively in tropical regions of the
Old World.
 With the exception of gibbons, living apes have relatively long arms,
short legs, and no tails.
 Although all nonhuman apes spend time in trees, only gibbons and
orangutans are primarily arboreal.
 Social organization differs among the apes, gorillas and chimpanzees
are highly social.
 Finally, compared to other primates, apes have a larger brain in
proportion to their body body size, and their behavior is more flexible.

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These two characteristics are especially prominent in the next group we’ll consider,
the hominins. (Campbell, 2014).
(a) Gibbons, such as this Muller’s Gibbon, are found only in Southeastern Asia.
Their very long arms and fingers are adaptations for brachiating (swinging by
the arms from branch to branch).

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(b) Orangutans are shy apes that live in the rain forests of Sumatra and Borneo. They
spend most of their time in trees; note the foot adapted for grasping and the opposable
thumb.
(C) Gorillas are the largest apes; some males are almost 2 m tall and weight about
200 kg. Found only in Africa, these herbivores usually live in groups of up to about 20
individuals

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(d) Chimpanzees live in tropical Africa. They feed and sleep in trees but also spend
great deal of time on the ground. Chimpanzees are intelligent, communicative,
and social.
(e) Bonobos are in the same genus (Pan) as chimpanzees but are smaller. They
survive today only in the African nation of Congo.
 Figure 34.44 Nonhuman apes

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(a) New World monkeys, such as spider monkeys (shown here), squirrels
monkeys, and Capuchins, have a prehensile tail (one adapted for
grasping) and nostrils that open to the sides.
(b) Old World monkeys lack a prehensile tail, and their nostrils open
downward. This group includes macaques (shown here), mandarils,
baboon, and rhesus monkeys.
 Figure 34.43 New World monkeys and Old World monkeys.

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LIFE SCIENCE FET
CLASS TEST 1 – 2018
INSTRUCTIONS AND INFORMATION
Read the following instructions carefully before answering the questions.
1. Answer ALL the questions.
2. Write ALL the answers in the ANSWER BOOK.
3. Start the answers to EACH question at the top of a NEW page.
4. Number the answers correctly according to the numbering system used in this
question paper.
5. Present your answers according to the instructions of each question.
6. Do ALL drawings in pencil and label them in blue or black ink.
7. Draw diagrams, tables or flow charts only when asked to do so.
8. The diagrams in this question paper are NOT necessarily drawn to scale.
9. Do NOT use graph paper.
10. You must use a non-programmable calculator, protractor and a compass, where
necessary. Write neatly and legibly.
SURNAME: ________________________________________ STUDENT NR. __________
QUESTION 1
[10]
Choose the alternative that best answers the question or completes the statement. Only
encircle the correct letter.
1.1 The three major lineages of mammals that had emerged: those leading to…
(a) Monotremes, Marsupials and Eutherians.
(b) Anthropoids and primates
(c) Monotremata, carnivora and xenarthral
(d) Monotremes and eutherians.
1.2 The fossil record indicates that anthropoids began diverging from other
primates about.
(a) 55 million years ago
(b) 160 million years ago
(c) 40 million years ago
(d) 10 million years ago
1.3 The ape group includes the genera Hylobates (gibbons), Pongo (orangutans),
Gorilla (gorillas), Pan (chimpanzees and bonobos), and Homo (humans).
(a) True
(b) False
1.4 Opossum, kangaroos, and koalas are examples of the group called.
(a) Marsupials
(b) Monotremes

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(c) Eutherians
(d) primates
1.5 This picture is an example of a
(a) Monotremes
(b) Hominins
(c) Mammal
(d) marsupials
QUESTION 2
[10]
Give the correct biological term for each of the following statements or definitions.
2.1 Egg-laying mammal.
2.2 A tree showing the evolutionary relationships among various biological species
2.3 Also known as placental mammals.
2.4 Travelling by swinging from branch to branch.
2.5 In most species, the nursing young are held within a maternal pouch called.
Question 3
3.1 Identify the three main groups of living primates.
3.2 Give a description of the following nonhuman apes from the pictures provided

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a.

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b.

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C.

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D.

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E.

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Question 4 [17 marks]
Draw and label a diagram representing a phylogenetic relationships of mammals.
Also clusters the eutherian orders into four main clades.
TOTAL: 60 MARKS

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MEMO
QUESTION 1
[10]
Choose the alternative that best answers the question or completes the statement. Only
encircle the correct letter.
1.1The three major lineages of mammals that had emerged: those leading to…
(a)Monotremes, Marsupials and Eutherians.
(b)Anthropoids and primates
(c) Monotremata, carnivora and xenarthral
(d) Monotremes and eutherians.
1.2 The fossil record indicates that anthropoids began diverging from other primates
about.
(a) 55 million years ago
(b) 160 million years ago
(c) 40 million years ago
(d)10 million years ago
1.3 The ape group includes the genera Hylobates (gibbons), Pongo (orangutans),
Gorilla (gorillas), Pan (chimpanzees and bonobos), and Homo (humans).
(a)True
(b) False
1.4 Opossum, kangaroos, and koalas are examples of the group called.
(a) Marsupials
(b) Monotremes
(c) Eutherians
(d) Primates
1.5This picture is an example of a
(a)Monotremes
(b)Hominin

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(c) Mammal
(d)marsupials
QUESTION 2
[10]
Give the correct biological term for each of the following statements or definitions.
2.1 Egg-laying mammal. Monotremes
2.2 A tree showing the evolutionary relationships among various biological species.
Phylogenetic tree
2.3 Also known as placental mammals. Eutherians
2.4 Travelling by swinging from branch to branch. Brachiating
2.5 In most species, the nursing young are held within a maternal pouch called. A
marsupium.
Question 3 [23 marks]
3.1
(a) The lemurs of Madagascar and the lorises and bush babies of tropical Africa
and Southern Asia;
(b) the tarsiers, which live in the southeastern Asia; and
(c) the anthropoids, which involves monkeys and apes and are found worldwide
[8 marks]
3.2
a. Gibbons, such as this Muller’s Gibbon, are found only in Southeastern Asia.
Their very long arms and fingers are adaptations for brachiating (swinging by
the arms from branch to branch).
b. Orangutans are shy apes that live in the rain forests of Sumatra and Borneo.
They spend most of their time in trees; note the foot adapted for grasping and
the opposable thumb.
c. Gorillas are the largest apes; some males are almost 2 m tall and weigh about
200 kg. Found only in Africa, these herbivores usually live in groups of up to
about 20 individuals

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d. Chimpanzees live in tropical Africa. They feed and sleep in trees but also spend
great deal of time on the ground. Chimpanzees are intelligent, communicative,
and social.
e. Bonobos are in the same genus (Pan) as chimpanzees but are smaller. They
survive today only in the African nation of Congo.
[15 marks, 3 per each]
Question 4
[17 marks]
TOTAL: 60 MARKS

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PRACTICAL
TOPIC: MAMALIAN DIVERSITY
INSTRUCTIONS AND INFORMATION
Read the following instructions carefully before answering the questions.
1. Answer ALL the questions.
2. Write ALL the answers in the ANSWER BOOK.
3. Start the answers to EACH question at the top of a NEW page.
4. Number the answers correctly according to the numbering system used in this question
paper.
5. Present your answers according to the instructions of each question.
6. Do ALL drawings in pencil and label them in blue or black ink.
7. WRITE NEATLY AND LEGIBLY
Question 1 [20 MARKS]
1.1 A phylogenetic tree of primates. The fossil record indicates that anthropoids
began diverging from other primates about 55 million years ago. New World
monkeys, Old World monkeys, and apes (the clade that includes gibbons,
orangutans, gorillas, chimpanzees, and humans) have been evolving as
separate lineages for more than 25 million years. The lineages leading to
humans branched off from other apes sometimes between 6 and million years
ago.
Draw a detailed diagram to support the above statement.
Question 2 [28 marks]
2.1 Contrast monotremes, marsupials, and eutherians in terms of how they bear
young.
2.2 identify at least five derived traits of primates.
2.3 Make connections. Develop a hypothesis to explain why the diversity of
mammals increased in the Cenozoic. Your explanation should consider mammalian
adaptations as well factors such as mass extinctions and continental drift.
TOTAL: 48 MARKS

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Practical Memorandum.
Question 1 [20 marks]
1.1
Question 2 [28 marks]
2.1 Monotremes lay eggs. Marsupials give birth to very small live young that attach
to a nipple in the mothers’ pouch, where they complete development. Eutherians
give birth to more developed live young. [5 marks]
2.2 Hand and feet adapted for grasping, flat nails, large brain, forward looking eyes
on a flat face, parental care and moveable big toe and thumb. [9 marks]
2.3
 Mammals are endothermic, enabling them to live in a wide range of habitats.
 Milk provides young with balanced set of nutrients, and hair and layer of fat
under the skin help mammals retain heat.
 Mammals have differentiated teeth, enabling them to eat many different kinds
of food.
 Mammals also have a relatively large brains, and many species are capable
learners.
 Following a mass extinction at the end of the Cretaceous period,
 the absence of large terrestrial dinosaurs may have opened many new
ecological niches to mammals,
 promoting an adaptive radiation.

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 Continental drift also isolated many groups of mammals from one another.
Promoting the formation of many new species.
[14 marks]
TOTAL: 48 MARKS

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REFERENCE LIST
Campbell, NA. Cain, ML. Jackson, RB. Reece, JB. Urry, LA. Wasserman, SA.
Minorsky, SA. Campbell Biology. A Global Approach. Tenth Edition. Global edition.
2014
Mayle, B.A. (1994). Roe Deer Biology and Management. Bulletin 105. Forestry
Commission, Edinburgh.
Waters, PD. Dobigny, G. Waddell PJ. Robison, TJ. Evolutionary history of Line-1 in
the major clades of placental mammals. PLoS ONE, 2007, vol.2 pg. e158